Gilmore served as governor of Virginia from 1998-2002, and was the chairman of the Republican National Committee (RNC) in 2001. He ran an unsuccessful Senate campaign in 2008 and an unsuccessful presidential campaign in 2016.

The Organization for Security and Cooperation in Europe is an intergovernmental organization comprised of 57 countries focused on security and rights issues.

Trump also sent his pick for ambassador to Saudi Arabia to the Senate for confirmation. The president announced earlier this week that he intended to nominate retired Gen. John Abizaid for the post, which has been unfilled for the past 22 months.

The vacancy became particularly notable in recent weeks amid mounting tensions between the U.S. and Saudi Arabia over the killing of journalist Jamal Khashoggi.

Abizaid, who currently serves as a visiting fellow at Stanford University, is a former head of U.S. Central Command and is well-versed in the politics of the Middle East. He retired from the military in 2007.

Trump also sent the Senate nominations for ambassadors to Macedonia, Australia, South Africa and Iraq.